Aortic valve endocarditis due to abiotrophia defectiva: a rare etiology.

Abiotrophia defectiva is a rare cause of infective endocarditis. Besides an association with often negative blood cultures and difficult treatment, high rates of relapse and higher mortality than endocarditis caused by other viridans streptococci are known features of this entity. We report on the surgical and medical management of the aortic valve endocarditis caused by Abiotrophia defectiva in a 19-year-old patient. To the best of our knowledge, this is the first case of a patient to have Down syndrome and Abiotrophia defectiva endocarditis requiring aortic valve replacement.